Hydraulically operated hand tools

ABSTRACT

A hydraulically operated tool for cutting multi-strand cable comprises a pair of jaws mounted on a linkage to be opened and closed by a hydraulic piston and cylinder unit. To ensure effective cutting of the cable a cable grip is provided which is manually operable and comprises a pair of jaws close to the cutting jaws of the tool and movable to clamp and release a cable to be cut.

United States Patent Grante et al. [4 1 Aug. 22, 1972 [54] HYDRAULICALLYOPERATED HAND 2,791,028 5/1957 Bidin ..30/l80 TOOLS 3,004,339 lO/ 1961Townshend ..30/l24 [72] Inventors: Rolph Grante, Vancouver; Byron AndreBurnaby British Columbia both of Canada 73 Assignee: Dynamic Tools Ltd.,Vancouver, ma y Examiner-Theron Condo" British Columbia, CanadaAssistant Examiner-J. C. Peters AttorneyFetherstonhaugh & Co. [22]Filed: July 23, 1970 [21] Appl. No.: 57,515 I [57] I ABSTRACT 52 11.5.CI ..30/124- A hydraulically operated tool for cutting multi strand [51]Int. Cl.- .t ..B2 6b 17/02 v a omprises a pair of jaws mounted on alinkage 2 [58.] Field ofSearch....30/9 2,96, 124, 134; 87/95 A; b p nand ed by a hydraulic piston and a 29/203 DT, 203 H, 203 P cylinderunit. To ensure effective cuttingof the cable a cable 'grip'is providedwhich is' manually operable and comprises a pair of jaws close to thecutting jaws [56] References Clt-ed of the tool and movable to clamp andrelease a cable UNITED STATES PATENTS to be 2,050,449 8/1936 Mute'r..30/ 124 X 9 Claims, 5 Drawing Figures I70 I?! 14/ /73 1 I74 I! 5 W a14s I Q Q I63 746 I47 2 154 I us 156 I59 I40 I I50 B6 131 1a --4 a, weI27 #22 52 he 40 43 "e Q J 25 34 I0 PATENTED M1822 m2 SHEET 1 0F 2mvem'Qas ROLPH GRANTE ANDRE BYRON ATTORN 5 HYDRAULICALLY OPERATED HANDTOOLS This invention is concerned with hydraulically operated hand toolsof the kind having a set of jaws movable towards and away from eachother.

A hand tool exemplary of the kind with which this invention isconcerned, is described in US. Pat. No. 2,791,028 issued May 7, 1957 toPeter Bidin and while it will be apparent that this invention has otherapplications, it has been developed, in its several aspects, as animprovement of the Bidin tool.

In general terms theBidin tool comprises a pair of handles, a pumpoperated by one of the handles and adapted to operate a ram on thehousing on which the handles are mounted. The ram actuates, through anappropriate linkage, a pair of cutting jaws.

A difficulty of tools of the Bidin type has been that they cannoteffectively be used for cutting multistranded cable for the jaws havetended to follow the lay of the strands of the cable or the cable hasmoved within the jaws because of the lay of the strands of the cable.

To overcome this disadvantage there is provided, according to anotheraspect of this invention, a hydraulically operated hand tool for cuttingcable having a manually operated cable grip arranged to grip cableadjacent to the cutting jaws of the tool said grip comprising a pair ofgripper jaws each having a cable gripping surface, and an operatingmechanism for moving the gripper jaws between open and closed positions.

It is desirable that the cable gripping surfaces be formed on partswhich are separable from the jaws themselves and to this end they may bein the form of blocks mounted upon the jaws and having part-circularsectioned gripping surfaces. To render the blocks suita ble fordifferent sizes of cable it is desirable to form the blocks with severaldifferently sized semi-circular sectioned grooves and for the blocks tobe rotatable to bring one or the other of the grooves into an operativeposition.

It will be appreciated that by having the cable grip operating mechanismmanually operated the cable can be engaged by the cable grip prior tothe cutting operation rather than relying on the cutting action to bringcable grips into operation.

An embodiment of this invention is illustrated in the accompanyingdrawings in which,

FIG. 1 is a front view, partly in section, of a tool according to thisinvention, especially adapted for cutting multi-strand cable,

FIG. 2 is a detail of the embodiment of FIG. 1, partly in section and inwhich certain parts are removed in the interest of clarity,

FIG. 3 is a cross-sectional view through the lower end of the ramcylinder and the pump of the tool taken on the line 3-3 of FIG. 5.

FIG. 4 is a cross-section on the line 4-4 of FIG. 3, and

FIG. 5 is a cross-section on the line 55 of FIG. 4.

The tool is, in many respects, similar to the Bidin tool. It comprises apair of handles and 11 connected to a generally cylindrical casting 12which constitutes the ram housing. At the upper end of the ram housing ajaw supporting structure 13 is mounted and this carries the cutter jaws,which are generally indicated at 14, and their associated linkage. Thecable gripping mechanism generally indicated at 15 is also carried onthe supporting structure 13.

The ram housing is a generally cylindrical casting which has projectingdownwardly from one side thereof, a sleeve and from the opposite sidethereof, an arm 21.

The sleeve 20 has an axial passage 22 which is of reduced diameter atits upper end 23 so that a shoulder 24 (FIG. 3) is formed at thetransition from the larger to the smaller diameter sections of thepassage. The lower edge of the sleeve has a circumferential section 25cut away to provide, at each end of that section, a stop. The purpose ofthe stops is described hereinafter.

The handle 11 is accommodated in sleeve 20 and has an upper portion of aslightly lesser diameter than the reduced diameter of section 23 ofsleeve 20 so as to be rotatable therein. The portion 30 projects outsidethe sleeve 20 and is secured in position by circlip 31 located in anappropriate groove in the portion 30.

Immediately below the portion 30 and accommodated in the larger diametersection of passage 22, there is on handle 11 an eccentric section 32which cooperates, as described hereinafter, with a push rod to allow thecutter jaw to open. Below the eccentric, the handle part 33 within thesleeve is of circular section and is provided with a radial peg 34 whichprojects into the cutaway section 25 of the lower edge of the sleeve andcooperates with the stops formed by that section to limit the rotarymovement of the handle within the sleeve between positions correspondingto the extreme positions of the push rod controlled by eccentric section32.

The arm 21 projecting downwardly from the side of the ram housingopposite to the sleeve 20 terminates in an eye to which the handle 10 ispivoted.

The handle 10 is in the form of a bell crank of which the short arm 41and the region of the pivot are bifurcated. The bifurcated pivot regionis located over the eye 40 and the pivot pin 42 passed through the eyeand corresponding holes in the handle to mount the handle for pivotalmovement on the arm 21. A pin 43 extends between the bifurcated sectionsof the arm 41 remote from pivot pin 42 and a saddle 44, FIG. 3, connectsthat pin to the outer end of a piston rod of the hydraulic pump of thetool.

The lower end of the housing 12 is closed by a base 50. Screwed into anappropriately threaded opening 51 in the bottom of the base is a pumpcylinder 52 (FIG. 3). Within the cylinder 52 a piston 53 is slidablylocated and has a piston rod 54 which projects to the outside-of thecylinder through a centrally apertured screw threaded piston rod guide56. A packing element 55 is located around the piston rod to preventleakage of fluid therepast.

The outer end of the piston rod 54 has an annular groove 58 within whichthe saddle 44 of the handle 10 is located. Thus it will be seen thatmovement back and forth of handle 10 towards handle 11 causesreciprocation of rod 54 and piston 53.

The base 50 is located in position within the housing 12 by a circlip 60and by a radially disposed grub screw (not shown in the drawings)located in a hole in the wall of the housing 12. The ram cylinder(described later) which is screw fitted into the base abuts the upperend of the housing and also serves to positively locate the base 50.

Surrounding the ram cylinder in the space between the outer surface ofthe ram cylinder and the inner surface of the housing 12 is a flexibleand resilient bag reservoir 71, the adoption of which renders the deviceuseful for operation in any position inasmuch as, the bag, beingdistendable ensures that the pump always has fluid available to it. Thegeneral principle of this flexible bag reservoir is described moreparticularly in Bidins US. Pat. No. 2,618,929 issued Nov. 25, 1952. Inthat patent the reservoir is shown as a space sealed off by an annularpiston which is spring urged always to maintain fluid available for thepump; however, it is to be appreciated that mechanically, the action ofthe flexible bag described herein is much the same as that earlier Bidinarrangement.

The bag forming the reservoir is firmly secured at its lower end 72between the inner wall of the housing 12 and the adjacent surface of thebase 50 within a groove formed around the upper and outer edge of thebase. The upper end 73 of the reservoir is bonded to the outer surfaceof the ram cylinder.

The ram cylinder comprises a tube externally threaded at its lower end74 for location in a correspondingly threaded central recess 75 in theupper surface of base 50 and having its upper end located in the recess76 in the axial end closure wall 12a of the housing 12.

Slidably located within the ram cylinder is a piston 78 secured on apiston rod 79. The rod extends through a central opening in the end wall12a of the ram housing 12 for connection, as described hereinafter, tothe jaw operating linkage.

The base 50 includes the valve passages to provide fluid communicationbetween the reservoir, the ram cylinder and the pump.

A main passageway 80 (FIG. 3) extends diametrically across the base andcomprises a first section 81 of relatively large diameter, a secondsection 82 of smaller diameter than section 81, the shoulder of thetransition between the two diameters constituting a seat 83 for the ballvalve 84. There is a third section 85 of lesser diameter than the secondsection and a fourth section 86 of similar diameter to the secondsection. The fourth section registers with an opening 87 through thewall of housing 12 into the sleeve for handle 11. For the purpose ofassembling the tool a hole 88 is formed in the wall of sleeve 20directly opposite to the opening 87 and after assembly that opening isplugged as at 89. The transition between the diameters of the second andthird sections constitutes a seat 90 for ball valve 91.

The ball valve 84 is spring loaded by a coil spring 92 towards the seat83 and the spring is retained by a screw 93. The screw 93 has a smallspigot 94 which extends axially within the spring 92 so as to guide thespring and the ball 84 to effect a positive opening and closing actionof the ball valve and thus to prevent flutter which might occur in theabsence of the spigot.

Located in the second section 82 of passage 80 and between the balls 84and 91 is a spacer piece 95 the action of which is describedhereinafter.

A stem 96 is slidably located in the fourth section of the passageway 80and extends through opening 87 into the sleeve 20 to be moved by theeccentric portion 32 of the handle 1 1 when that handle is turned aboutits own axis. The stem 96 has an annular groove within which an O-ring97 is located, the O-ring sealing the small space between the stem andthe surface of the section 86 of passage 80.

The inner end of the stem 96 has, formed integrally therewith, a pushrod 98 which projects into the section of passageway 80 and is of suchlength that when the handle 11 is turned to move the stem inwardly, thepush rod lifts the ball 91 from its seat and causes that ball to pushspacer piece onto ball 84 and lift that ball from its seat 83 againstthe action of spring 92.

It will be appreciated that the opening 88 in the outer wall of sleeve20 allows the stem 96 to be inserted. The

balls 91 and 84 and the spacer piece 95 and the spring 92 are insertedfrom the other end of passage 80.

A bore 99 is formed between the recess at the upper end .of the pump 52and the second section 82 of the passage 80. Another bore 100 extendsbetween the section 86 of passageway 80 and the reservoir 71; A thirdbore 101 communicates between the first section 81 of passageway 80 andthe lower port of ram cylinder 70.

A bore 102 (seen only in FIG. 5) extends right through the base 50 tothe reservoir 71 and this serves for filling or topping up thereservoir. The lower end of the bore is closed by a screw and washer.

A radial bore 103 extending normally to the passageway 80 andcommunicating with the second section 82 of that passage 80 is formed inthe base. The innermost part 104 of bore 103 which opens into passageway80 is of smaller diameter than the remainder of that bore and theshoulder of the transition to that smaller diameter constitutes a seatfor a ball 105. The outer end of the bore is threaded to receive a screw106, and an axial groove 107 is made in the wall of the bore. The screw106 is grooved to receive an O- ring 106a to prevent the passage offluid past the screw except through groove 107 which terminates inwardlyof the O-ring. Between the innermost end of the screw 106 and the ballare located a pair of dish-shaped springs 108 which load the balltowards its seat.

A bore 109 is made between the groove 107 and the upper surface of thebase 50 in the region where that upper surface closes the reservoir 71so that when the ball 105 is moved from its seat fluid can flow from thesection 82 of the passageway 80 into the bore 103 through groove 107,into the bore 109 and into the reservoir 71.

The operation of the pump and ram is as follows: When the handle 1 1 isturned to the position illustrated in FIG. 3, with the push rod 98withdrawn from the ball 91, movement of handle 10 away from the handle11 induces the suction stroke of the pump 52. Ball 91 is lifted from itsseat and fluid drawn into the pump from the reservoir through bores 100and 99. Ball 84 is maintained on its seat by spring 92.

As the handle 10 is moved towards handle 11 fluid is pumped through bore99 causing the ball 91 to move on to its seat and causing the ball 84 tobe lifted from its seat. The fluid then flows, through bore 101, to theram cylinder to extend the ram.

When it is desired to permit the ram to be retracted, the handle 11 isturned and the eccentric 32 causes balls 91 and 84 to be lifted fromtheir respective seats by the push rod 98 and the spacer piece 95. Fluidcan flow from the ram cylinder to the reservoir through bore 101,passage 80 and bore 100.

In the event that the pressure in the ram cylinder exceeds a safemaximum (because the material being cut is too strong or the operatorcontinues to pump after the ram has been fully extended) pressure insection 82 of the passage builds up applying a pressure on ball throughbore 104. The spring loading of ball 105 is set by screw 106 so thatwhen a pressure in excess of the maximum permissable pressure exists inthe cylinder, the ball 70 is lifted from its seat and fluid flowsthrough bores 104 and 109 to the reservoir thus preventing overloadingand consequent damage to the blades.

In earlier tools it was found that the cutter blades would cross beforethe maximum premissible pressure was reached and this effect causeddamage to those blades. To overcome this disadvantage the upper end ofthe ram cylinder is internally threaded as at 110 to cooperate with anend closure cap 111 which is externally threaded. The inner end surface112 (i.e. the end nearest to piston 78) presents a shoulder which actsas an abutment to limit the outward movement of the ram by coacting withthe piston of the ram. A screwthreaded hole (not shown) is formedradially through the wall of the ram cylinder so that a set screw can beintroduced into that hole to lock the relative positions of the cap 111and the cylinder. The cap is so positioned that the piston and theabutment shoulder 112 come into contact just as, or slightly before, thecutter blades generally indicated at 14 are closed so that those bladescannot cross over each other or be pressed together with undue force. Itwill be appreciated that the cap can be adjusted to obtain this desiredposition.

The jaw support structure or jaw head 13 (FIG. 1) is secured to theupper end of the ram housing 12 by connector 120. The upper region ofthe housing 12 is externally screw threaded as at 121 and has acarefully finished annular shoulder 122 (FIG. 2). That shoulder 122 isfinished to be normal to the axis of the ram.

The lower end of the support 13 is recessed as at 123 to accommodate theupper reduced diameter section of the housing and has an accuratelyfinished annular surface 124 for cooperation with shoulder 122 of theram housing so that when those two surfaces are brought firmly togetherthe housing and the support are accurately aligned.

Above surface 124 a groove 125 is cut around the outside surface of thesupport structure to accommodate one or more spring steel split rings126. The connector is in the form of a sleeve which is internally screwthreaded for cooperation with the threads 12] of the upper end of theram housing and has at its upper edge a radially inwardly extendingflange 127 which engages the split rings 126. To assemble the jawsupport structure to the ram housing, the connector 120 is located onstructure 13 above the groove and the ring 126 is located in position.The structure 13 and housing 12 are then brought together and theconnector screwed tightly on to the housing. The split rings will flexas the connector is screwed down to an extent which will allowface-to-face contact between the surfaces 122 and 124 thus accuratelyaligning the housing and the support structure.

The support structure is hollow and is slotted as at 130 and 131 toaccommodate projecting ears 132 and 133 of a cross head 134 locatedwithin the structure.

The cross head is secured to the upper end of the ram piston rod 79.Located within the support structure and working against the action ofthe ram is a coil spring 135.

To the ears 132 and 133 a pair of links 136 and 137 are respectivelypivoted on pins 138 and 139. Between the outer ends of links 136, thetail 140 of a jaw 14] is pivoted on pin 142 and similarly, between theouter ends of links 137 the tail 143 of a jaw 144 is pivoted on pin 145.These are the jaws previously mentioned as being generally indicated-at14.

The jaws 141 and 144 are pivoted to the support structure about pins 146and 147, respectively, which extend across the gap between oppositesides of the slotted upper end 148 of the structure. Thus, movementupwardly of the cross head 134 causes the jaws to be closed and movementdownwardly of that head causes the jaws to be opened. I

For cutting bar or rod, the device so far described is sufiicient, butto facilitate thecutting of multi-strand wire or cable it is desirableto have'a cable grip. This grip comprises an operating handle 150pivoted on a stud 151 screwed into an'appropriately threaded hole on thejaw support structure. The handle is notched at 152 to cooperate with apeg 153 to limit the movement of the handle in one, the closing,direction. The upper end of the handle has two laterally projecting arms154 and 155, said arms being apertured to receive pivot pins 156 and 157respectively upon which pairs of links 158 and 159, respectively, aremounted. A pivot pin 160 connects the free ends of the pair of links 158to a clamping or gripper jaw 161. Similarly pivot pin 162 connectsthe'free ends of links 159 to a clamping or gripper jaw 163. The jaws161 and 163 are pivotally mounted on extensions of pivot pins 146 and147, respectively, which also pivotally mount the cutting jaws of thetool.

Thus, as the handle 150 is moved to the right as viewed in FIG. 1, thegripper jaws will be opened and as it is moved, from its jaw openingposition, to the left to an overcenter position abutting stud 153, thegripper jaws will be closed.

At the upper ends of clamping jaws 161 and 163 there are clampingelements and 171, respectively. Elements 170 and 171 are pressed on tostuds 173 and 174 projecting from their corresponding jaws and aregenerally block-shaped with partcircular section grooves formed in eachsurface parallel to the studs upon which they are mounted. The curvatureof the groove in each surface of one element is different from theothers of that element, but the blocks are similar so that by turningthe elements about the studs upon which they are mounted, a pair ofsimilar grooves, one on each block, can be brought into opposition. Inthis way a clamp suitable for difl'erent cable diameters is provided.

It will be appreciated that the tool herein described has severaladvantages over prior art arrangements and particular its abilityreliably to cut multi-strand cable.

What is claimed is:

1. A cable cutter tool comprising a support, a pair of cutter jawshaving cutting edges and pivotally mounted on the support for movementtowards and away from each other, power means connected to the cutterjaws to move said jaws towards each other in a cutting action, a pair ofgripper jaws pivotally mounted on the support beside the cutter jaws formovement towards and away from each other, and a gripper element movablymounted on each gripper jaw, said gripper elements being mounted on thegripper jaws so that when said gripper jaws move towards each other thegripper elements move towards each other adjacent the cutting edges ofthe cutter jaws, each gripper element having a plurality of differentcable gripping surfaces formed therein, and said elements being movablerelative to each other and the gripper jaws to bring selected ones ofsaid gripping surfaces into operative position.

2. A cutter tool as claimed in claim 1 including manually-operable meansconnected to the gripper jaws for moving said gripper jaws towards andaway from each other.

3. A cutter tool as claimed in claim 1 in which each gripping surface ofthe gripper elements comprises a part circular section groove.

4. A cutter tool as claimed in claim 1 in which each gripper elementcomprises a block pivotally mounted on one of said gripper jaws. v

5. A cutter tool as claimed in claim 1 in which said cutter jaws arepivotally mounted on pins carried by the support, and said gripper jawsalso are pivotally mounted on said pins.

6. A cutter tool as claimed in claim 1 in which said gripper jaws areswingably mounted on pins carried by the support, said gripper elementsbeing mounted on ends of the gripper jaws on one side of said pins andthe gripper jaws having free ends on the opposite side of said pins, andincluding a handle swingably mounted on a pin carried by the supportbetween the free ends of the gripper jaws, anns on the handle near thepin thereof and extending towards said gripper jaw free ends, and linksconnecting the arms to said free ends whereby swinging of the handlecauses the gripper jaws to swing to move the gripper elements towardsand away from each other.

7. A tool for a cable cutter having cutter jaws, comprising a pair ofgripper jaws adapted to be mounted on a cable cutter adjacent cutterjaws thereof for movement towards and away from each other, and agripper element movably mounted on each gripper jaw, said gripperelements being mounted on the gripper jaws so that when said gripperjaws move towards each other the gripper elements move towards eachother, each gripper element having a plurality of different cablegripping surfaces formed therein, and said elements being movablerelative to each other and the gripper jaws to bring selected ones ofsaid gripping surfaces into operative position.

8. A tool as claimed in claim 7 including manuallyoperable meansconnected to the gripper jaws for mov ing said gripper jaws towards andaway from each other. i

9. A tool as claimed in claim 7 in which each gripper element comprisesa block pivotally mounted on one of said gripper jaws.

1. A cable cutter tool comprising a support, a pair of cutter jawshaving cutting edges and pivotally mounted on the support for movementtowards and away from each other, power means connected to the cutterjaws to move said jaws towards each other in a cutting action, a pair ofgripper jaws pivotally mounted on the support beside the cutter jaws formovement towards and away from each other, and a gripper element movablymounted on each gripper jaw, said gripper elements being mounted on thegripper jaws so that when said gripper jaws move towards each other thegripper elements move towards each other adjacent the cutting edges ofthe cutter jaws, each gripper element having a plurality of differentcable gripping surfaces formed therein, and said elements being movablerelative to each other and the gripper jaws to bring selected ones ofsaid gripping surfaces into operative position.
 2. A cutter tool asclaimed in claim 1 including manually-operable means connected to thegripper jaws for moving said gripper jaws towards and away from eachother.
 3. A cutter tool as claimed in claim 1 in which each grippingsurface of the gripper elements comprises a part circular sectiongroove.
 4. A cutter tool as claimed in claim 1 in which each gripperelement comprises a block pivotally mounted on one of said gripper jaws.5. A cutter tool as claimed in claim 1 in which said cutter jaws arepivotally mounted on pins carried by the support, and said gripper jawsalso are pivotally mounted on said pins.
 6. A cutter tool as claimed inclaim 1 in which said gripper jaws are swingably mounted on pins carriedby the support, said gripper elements being mounted on ends of thegripper jaws on one side of said pins and the gripper jaws having freeends on the opposite side of said pins, and including a handle swingablymounted on a pin carried by the support between the free ends of thegripper jaws, arms on the handle near the pin thereof and extendingtowards said gripper jaw free ends, and links connecting the arms tosaid free ends whereby swinging of the handle causes the gripper jaws toswing to move the gripper elements towards and away from each other. 7.A tool for a cable cutter having cutter jaws, comprising a pair ofgripper jaws adapted to be mounted on a cable cutter adjacent cutterjaws thereof for movement towards and away from each other, and agripper element movably mounted on each gripper jaw, said gripperelements being mounted on the gripper jaws so that when said gripperjaws move towards each other the gripper elements move towards eachother, each gripper element having a plurality of different cablegripping surfaces formed therein, and said elements being movablerelative to each other and the gripper jaws to bring selected ones ofsaid gripping surfaces into operative position.
 8. A tool as claimed inclaim 7 including manually-operable means connected to the gripper jawsfor moving said gripper jaws towards and away from each other.
 9. A toolas claimed in claim 7 in which each gripper element comprises a blockpivotally mounted on one of said gripper jaws.